If you are trying to keep a trunk load of items on hand for the zombie apocalypse, you can pretty much scratch most items off of your list with the Crovel. Carrying around an entire backpack full of equipment seems a little silly when you can have 13 tools on hand.
This awesome zombie-survival device has a shovel, serrated saw, knife-edge, and crow bar, pick axe, hammer, 15-feet of 550 paracord and so much more. There even appears to be a bottle opener for situations that might call for it. This wondrous multi-tool can be purchased for $99, and could probably also be used in some non-zombie scenarios as well.